Effect of MoS2 on the tribological properties of carbon fabric composites under wet conditions

2017 ◽  
Vol 232 (2) ◽  
pp. 126-135 ◽  
Author(s):  
Lehua Qi ◽  
Guangzhen Pan ◽  
Yewei Fu ◽  
Xiang Zhang ◽  
Xianghui Hou ◽  
...  
Keyword(s):  
Wear Resistance ◽  
Wear Rate ◽  
Tribological Properties ◽  
Carbon Fabric ◽  
Wear Performance ◽  
High Mechanical Strength ◽  
Wear Rates ◽  
Impregnation Technique ◽  
Fabric Composites ◽  
Wear And Friction

Carbon fabric reinforced phenolic composites are very attractive for use as friction materials under wet conditions due to their excellent self-lubricity, wear resistance, and high mechanical strength. However, brittle fracture of carbon fabric bundles during friction is one of the major problems that limit their application. In this work, MoS2 particles were used as additives and friction modifiers to improve the wear and friction behaviors. The composites containing different amounts of MoS2 particulates (0–20 wt%) were fabricated by impregnation technique. The influence of MoS2 on the tribological properties under oil-lubricated conditions has been studied systematically. The experimental results revealed that tribological characteristics such as coefficient of friction and wear resistance were changed significantly with the relative amount of MoS2. Addition of MoS2 within 15 wt% was found to decrease the wear rates of the composites, while 20 wt% MoS2-filled composites exhibited highest wear rate compared to other test samples. Increasing MoS2 content resulted in a rise in the wear rate of the counterparts. Wear mechanisms had been investigated by scanning electron microscope, which could support the observed wear performance.

Friction and Wear of Potassium Titanate Whisker Filled Carbon Fabric/Phenolic Polymer Composites

2015 ◽  
Vol 137 (1) ◽  
Author(s):  
Xinrui Zhang ◽  
Xianqiang Pei ◽  
Qihua Wang ◽  
Tingmei Wang
Keyword(s):  
Wear Rate ◽  
Friction And Wear ◽  
Dip Coating ◽  
Hot Press ◽  
Carbon Fabric ◽  
Potassium Titanate ◽  
Transfer Films ◽  
Fabric Composites ◽  
Phenolic Polymer ◽  
Press Molding

Carbon fabric/phenolic composites modified with potassium titanate whisker (PTW) were prepared by a dip-coating and hot-press molding technique, and the tribological properties of the resulting composites were investigated systematically using a ring-on-block arrangement under different sliding conditions. Experimental results showed that the optimal PTW significantly decreased the wear-rate. The worn surfaces of the composites and the transfer film formed on the counterpart steel ring were examined by scanning electron microscopy (SEM) to reveal the wear mechanisms. The transfer films formed on the counterpart surfaces made contributions to the improvement of the tribological behavior of the carbon fabric composites. The friction and wear of the filled carbon fabric composites was significantly dependent on the sliding conditions. It is observed that the wear-rate increased with increasing applied load and sliding speeds.

scholarly journals The Effect of Polytetrafluoroethylene (PTFE) Particles on Microstructural and Tribological Properties of Electroless Ni-P+PTFE Duplex Coatings Developed for Geothermal Applications

Coatings ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 670
Author(s):  
Gifty Oppong Boakye ◽  
Arna María Ormsdóttir ◽  
Baldur Geir Gunnarsson ◽  
Sandeep Irukuvarghula ◽  
Raja Khan ◽  
...  
Keyword(s):  
Wear Resistance ◽  
Tribological Properties ◽  
Complex Geometry ◽  
Corrosion And Wear ◽  
Functional Layer ◽  
Scaling Properties ◽  
Wear Rates ◽  
Mechanical And Tribological Properties ◽  
Duplex Coating ◽  
Wear Protection

The selection of electroless nickel-phosphorus plating (ENP) has been inclined towards their properties and advantages with complex geometry applications. These properties include coating uniformity, low surface roughness, low wettability, high hardness, lubricity, and corrosion- and wear-resistance. Materials used in geothermal environments are exposed to harsh conditions such as high loads, temperature, and corrosive fluids, causing corrosion, scaling, erosion and wear of components. To improve the corrosion- and wear-resistance and anti-scaling properties of materials for geothermal environment, a ENP duplex coating with PTFE nanoparticles was developed and deposited on mild steel within the H2020 EU Geo-Coat project. ENP thin adhesive layer and ENP+PTFE top functional layer form the duplex structure of the coating. The objective of this study was to test the mechanical and tribological properties of the developed ENP-PTFE coatings with varying PTFE content. The microstructural, mechanical and tribological properties of the as-deposited coating with increasing PTFE content in the top functional layer in the order: ENP1, ENP2 and ENP3 were evaluated. The results showed maximum wear protection of the substrates at the lowest load; however, increasing load and sliding cycles increased the wear rates, and 79% increased lubrication was recorded for the ENP2 duplex coating. The wear performance of ENP3 greatly improved with a wear resistance of 8.3 × 104 m/mm3 compared to 6.9 × 104 m/mm3 for ENP2 and 2.1 × 104 m/mm3 for ENP1. The results are applicable in developing low friction, hydrophobic or wear-resistive surfaces for geothermal application.

scholarly journals Sliding Wear of Conventional and Suspension Sprayed Nanocomposite WC-Co Coatings: An Invited Review

2021 ◽  
Author(s):  
R. Ahmed ◽  
O. Ali ◽  
C. C. Berndt ◽  
A. Fardan
Keyword(s):  
Wear Rate ◽  
Thermal Spray ◽  
Sliding Wear ◽  
Failure Modes ◽  
Thermal Spray Coatings ◽  
Annual Growth Rate ◽  
Total Energy Consumption ◽  
Wear Performance ◽  
Wear Rates ◽  
Spray Coatings

AbstractThe global thermal spray coatings market was valued at USD 10.1 billion in 2019 and is expected to grow at a compound annual growth rate of 3.9% from 2020 to 2027. Carbide coatings form an essential segment of this market and provide cost-effective and environmental friendly tribological solutions for applications in aerospace, industrial gas turbine, automotive, printing, oil and gas, steel, and pulp and paper industries. Almost 23% of the world’s total energy consumption originates from tribological contacts. Thermal spray WC-Co coatings provide excellent wear resistance for industrial applications in sliding and rolling contacts. Some of these applications in abrasive, sliding and erosive conditions include sink rolls in zinc pots, conveyor screws, pump housings, impeller shafts, aircraft flap tracks, cam followers and expansion joints. These coatings are considered as a replacement of the hazardous chrome plating for tribological applications. The microstructure of thermal spray coatings is however complex, and the wear mechanisms and wear rates vary significantly when compared to cemented WC-Co carbides or vapour deposition WC coatings. This paper provides an expert review of the tribological considerations that dictate the sliding wear performance of thermal spray WC-Co coatings. Structure–property relationships and failure modes are discussed to grasp the design aspects of WC-Co coatings for tribological applications. Recent developments of suspension sprayed nanocomposite coatings are compared with conventional coatings in terms of performance and failure mechanisms. The dependency of coating microstructure, binder material, carbide size, fracture toughness, post-treatment and hardness on sliding wear performance and test methodology is discussed. Semiempirical mathematical models of wear rate related to the influence of tribological test conditions and coating characteristics are analysed for sliding contacts. Finally, advances for numerical modelling of sliding wear rate are discussed.

En Wear-Resisting Properties of Epoxy/WC-Co/Al Coating on 300M Steel

2019 ◽  
Vol 1151 ◽  
pp. 47-53
Author(s):  
Feng Ding ◽  
Shu Qin Li ◽  
Ping Ze Zhang ◽  
Dong Bo Wei ◽  
Xiao Hu Chen ◽  
...  
Keyword(s):  
Wear Resistance ◽  
Rotational Speed ◽  
Steel Part ◽  
Curing Process ◽  
Wear Performance ◽  
Uncoated Sample ◽  
Surface Protection ◽  
Wear Rates ◽  
300M Steel ◽  
Al Coating

Based on surface protection problems of the steel part of the landing gear, wear-resisting properties of tungsten carbide-cobalt (WC-Co) particles reinforced epoxy (WRE) coatings were investigated in this paper. The curing process of WRE coating was analyzed by DSC, TG and IR. The wear performance under different rotational speed WRE coating was studied respectively. The specific wear rates of the WRE coating at 560 rpm and 840 rpm are 6.04 ×10−4mm3N−1m−1and 9.55 ×10−4mm3N−1m−1respectively, about only 60% of that of the uncoated sample. Thus, this could be summarized that WRE coating had a good wear resistance.

Effects of Tribo-Couple and Environmental Medium on the Tribological Properties of the Graphite/CaF2/TiC/Ni-Base Alloy Composite Coating

2013 ◽  
Vol 834-836 ◽  
pp. 644-648
Author(s):  
Bin Cai ◽  
Hua Bing Li ◽  
Ye Fa Tan ◽  
Hong Wei Li ◽  
Qi Feng Jing ◽  
...  
Keyword(s):  
Wear Rate ◽  
Composite Coating ◽  
Tribological Properties ◽  
Base Alloy ◽  
Alloy Coating ◽  
Dry Sliding ◽  
Wear Property ◽  
Alloy Composite ◽  
Nacl Solution ◽  
Wear Rates

The graphite/CaF2/TiC/Ni-base alloy composite coating was prepared on the surface of 45 carbon steel by plasma spray. Effects of loads, friction counterparts and lubricants on the tribological properties of the composite coating were investigated. The results show that the wear rate of the GCTN composite coating against Si3N4is 0.67×10-3mm3/m, which is about 2 times that against GCr15 steel, because Si3N4induces micro-cutting wear of the composite coating. Water and NaCl solution may induce increasing of friction coefficients and wear rates. Especially, wear rate of the GCTN composite coating in NaCl solution is increased by 3.1 times compared with those under dry sliding and water. The GCTN composite coating presents better anti-wear property than Ni-base alloy coating in different environmental mediums.

Wear Performance of the Plasma Sprayed Fine WC-Co Composite Powders Coatings

2012 ◽  
Vol 454 ◽  
pp. 144-147
Author(s):  
Lian Wei Yang ◽  
Jin Hui Li ◽  
Yun Dong ◽  
Xiao Ping Lin
Keyword(s):  
Wear Resistance ◽  
Brittle Fracture ◽  
Composite Coating ◽  
Plasma Spraying ◽  
Composite Coatings ◽  
Composite Powders ◽  
Wear Performance ◽  
Wear And Friction ◽  
Plasma Sprayed ◽  
Increasing Load

WC/Co; Composite coating; Plasma spraying; Friction and wear Abstract: WC- Co composite powders were synthesized by direct mechanical grinding in a rotary-vibration mill under 8h, and then analyzed by SEM and XRD. WC and WC/Co composite coatings were prepared by supersonic plasma spraying fine WC-Co composite powders. The wear and friction properties of both coatings were evaluated. The results showed that the wear resistance of the WC/Co composite coating was superior to that of the WC coating. The improvement in wear resistance of the WC/Co composite coating was attributed to its higher fracture toughness and adhesion strength as well as better thermal diffusivity. As for the WC/Co composite coating, the mechanism was mainly adhesion with micro-abrasion and fatigued-induced brittle fracture within splats, and the delamination along splat boundaries only occurred at high load. However, the failure of the WC coating was predominantly detachment of transferred film and brittle fracture within the splats and delamination along splat boundaries, which were enhanced with the increasing load.

scholarly journals Effect of WC Grain Size and Abrasive Type on the Wear Performance of HVOF-Sprayed WC-20Cr3C2-7Ni Coatings

Coatings ◽  
2020 ◽  
Vol 10 (7) ◽  
pp. 660
Author(s):  
Qun Wang ◽  
Yingpeng Zhang ◽  
Xiang Ding ◽  
Shaoyi Wang ◽  
Chidambaram Seshadri Ramachandran
Keyword(s):  
Grain Size ◽  
Wear Resistance ◽  
Wear Rate ◽  
Abrasive Wear ◽  
Wear Test ◽  
Binder Phase ◽  
Repeated Impact ◽  
Wear Performance ◽  
The Matrix ◽  
Three Body

In order to investigate the effect of WC grain size on coatings’ properties and abrasive wear performance, a few WC-20Cr3C2-7Ni coatings with three different WC grain sizes were deposited by the high-velocity oxy-fuel (HVOF) thermal spray process. The phase compositions, microstructures, and mechanical properties of the coatings were investigated. Furthermore, the two- and three-body abrasive wear performances of the three coatings were tested by using SiC and SiO2 abrasives, respectively. The results show that all the three coatings were composed of WC, Cr3C2, and the Ni binder as well as the (W,Cr)2C phase. The abrasive wear resistance of the WC-20Cr3C2-7Ni coating monotonously increased with increasing WC grain size when the SiC abrasive was used in the two- and three-body abrasive wear tests. However, the wear resistance trend was reversed when the SiO2 abrasive was used in the three-body abrasive wear test. The specific wear rate of the WC-20Cr3C2-7Ni coating exposed to the SiC abrasive under the two-body abrasive wear test was the largest. The wear resistance of the coatings was more significantly affected by the hardness of the abrasive particles than the size of carbides present within the coating. The high hardness of SiC can cut both the carbide and the binder phase of the WC-based cermet coatings, resulting in a high wear rate, whereas the low hardness of SiO2 cuts and/or scratches the binder initially, and then it dislodges the carbides from the matrix. The dislodged carbides which were subsequently pulled out from the matrix by the repeated impact of the SiO2 abrasives result in a milder wear rate.

What factors drive polyethylene wear in total knee arthroplasty?

2021 ◽  
Vol 103-B (11) ◽  
pp. 1695-1701
Author(s):  
John H. Currier ◽  
Barbara H. Currier ◽  
Matthew P. Abdel ◽  
Daniel J. Berry ◽  
Alexander J. Titus ◽  
...  
Keyword(s):  
Total Knee Arthroplasty ◽  
Wear Rate ◽  
Knee Arthroplasty ◽  
Patient Specific ◽  
Wear Performance ◽  
Thickness Change ◽  
Wear Rates ◽  
Tibial Insert ◽  
Total Knee

Aims Wear of the polyethylene (PE) tibial insert of total knee arthroplasty (TKA) increases the risk of revision surgery with a significant cost burden on the healthcare system. This study quantifies wear performance of tibial inserts in a large and diverse series of retrieved TKAs to evaluate the effect of factors related to the patient, knee design, and bearing material on tibial insert wear performance. Methods An institutional review board-approved retrieval archive was surveyed for modular PE tibial inserts over a range of in vivo duration (mean 58 months (0 to 290)). Five knee designs, totalling 1,585 devices, were studied. Insert wear was estimated from measured thickness change using a previously published method. Linear regression statistical analyses were used to test association of 12 patient and implant design variables with calculated wear rate. Results Five patient-specific variables and seven implant-specific variables were evaluated for significant association with lower insert wear rate. Six were significant when controlling for other factors: greater patient age, female sex, shorter duration in vivo, polished tray, highly cross-linked PE (HXLPE), and constrained knee design. Conclusion This study confirmed that knee wear rate increased with duration in vivo. Older patients and females had significantly lower wear rates. Polished modular tibial tray surfaces, HXLPE, and constrained TKA designs were device design factors associated with significantly reduced wear rate. Cite this article: Bone Joint J 2021;103-B(11):1695–1701.

Influence of h-BN fillers on mechanical and tribological properties of PP/PA6 blend

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Abhishek Vyas ◽  
Kawaljit Singh Randhawa
Keyword(s):  
Tensile Strength ◽  
Elastic Modulus ◽  
Wear Rate ◽  
Tribological Properties ◽  
Hexagonal Boron Nitride ◽  
Polyamide 6 ◽  
Content Type ◽  
Wear Rates ◽  
Mechanical And Tribological Properties ◽  
Lubricating Film

Purpose The purpose of this study is to improve the mechanical and tribological performance of polypropylene (PP) material. The influence of hexagonal boron nitride (h-BN) microparticles on mechanical and tribological properties of PP/polyamide 6 (nylon 6) (PA6) blend has been investigated in this paper. Design/methodology/approach Tensile strength, elongation, elastic modulus and Rockwell hardness were measured to identify the mechanical properties of materials. Coefficient of friction (COF) and wear rates of materials were measured with the help of a pin-on-disc tribometer to check the tribological behavior of blend and composite materials. Findings As a result, a small decrease in tensile strength and elongation and improvement in elastic modulus were found for PP/PA6 and PP/PA6/h-BN composite compared to pure PP. The wear rate of PP/PA6 blend and PP/PA6/h-BN composite was found low compared to pure PP matrix, while the COF of PP/PA6 blend was found slightly higher owing to the presence of harder PA6 matrix which was then improved by the h-BN filler reinforcement in PP/PA6/h-BN composite. The addition of PA6 in PP improved the wear rate of PP by 8–24%, whereas the addition of h-BN microparticles improved the wear rate by 22–50% and 24–44% compared to pure PP and PP/PA6 blend, respectively, in different parameters. Originality/value Modulus of elasticity and hardness of pure PP was enhanced by blending with PA6 and was further improved by h-BN fillers. The addition of PA6 in PP improved the wear rate, while h-BN fillers were found effective in reducing the COF by generating smooth thin lubricating film.

TEMPERATURE-DEPENDENT EFFECT OF BORIC ACID ADDITIVE ON SURFACE ROUGHNESS AND WEAR RATE

2017 ◽  
Vol 24 (Supp01) ◽  
pp. 1850005
Author(s):  
ŞERAFETTIN EKİNCİ
Keyword(s):  
Surface Roughness ◽  
Friction Coefficient ◽  
Wear Rate ◽  
Boric Acid ◽  
Tribological Properties ◽  
Internal Combustion Engines ◽  
Wear Behavior ◽  
Important Place ◽  
Mechanical And Tribological Properties ◽  
Wear And Friction

Wear and friction hold an important place in engineering. Currently, scientific societies are struggling to control wear by means of studies on lubricants. Boric acid constitutes an important alternative with its good tribological properties similar to MO2S and graphite alongside with low environmental impacts. Boric acid can be used as a solid lubricant itself whereas it can be added or blended into mineral oils in order to yield better mechanical and tribological properties such as low shear stress due to the lamellar structure and low friction, wear and surface roughness rates. In this study, distinguishing from the literature, boric acid addition effect considering the temperature was investigated for the conventional ranges of internal combustion engines. Surface roughness, wear and friction coefficient values were used in order to determine tribological properties of boric acid as an environmentally friendly additive and mineral oil mixture in the present study. Wear experiments were conducted with a ball on disc experimental setup immersed in an oil reservoir at room temperature, 50[Formula: see text]C and 80[Formula: see text]C. The evolution of both the friction coefficient and wear behavior was determined under 10[Formula: see text]N load, at 2[Formula: see text]m/s sliding velocity and a total sliding distance of 9000[Formula: see text]m. Surface roughness was determined using atomic-force microscopy (AFM). Wear rate was calculated utilizing scanning electron microscope (SEM) visuals and data. The test results showed that wear resistance increased as the temperature increased, and friction coefficient decreased due to the presence of boric acid additive.

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